Piston packing



Odi. 31, 1944. D M, SMITH v 2,361,904

PIs'roN PACKING Filed Jan. 6. 1940 Patented oei. 31, 1944` A PISTON PACKING Dallas M. Smith,

Kirkwood, Mo., assigner to McQnay-Norrls Manufacturing Company, St. Leuk, Mo.. a corporation of Delaware Application January 6, 1940, Serial No. 312,759

3 Claims. (Cl. 309-45) My invention relates -to piston and more particularly to multiple-piece piston packings having a plurality of cylinder contacting surfaces arranged and adapted to provide an effective sealbetween the piston and the wall of the cylinder in which it reciprocates.

Heretofore, in piston packings comprising a plurality of flat, wafer rings arranged in pairs, with each pair separated by a spacer having'oil passages, therethrough, the spacer usually was formed by a cast iron ring of generally rectangular cross-section and, therefore, the bounding walls of the oil passages extending through the spacer were of a length equal to the thickness of the ring, that is, they were equal to the radial depth from the front to the rear face of the spacer ring. In many cases carbon collected on these bounding walls and often many, if not all, of the passages through the ring became clogged and olzistructedy so as to prevent eiiective operation of the packing structure as an efiicient sealing means.

Having in` mind these and other structural deiiciencies of piston packings as used heretofore, my invention contemplates a piston packing comprising a plurality of resilient ring members formed preferably of ribbon steel and arranged to contact the cylinder wall. Usually positioned between the rear faces of the ring members and the bottom of the ring groove in which the members are used is a. ring expander` adapted to engage the rear faces of the ring members and to exert radial pressure thereon so that the ring members, in turn, exert a high pressure per unit of contacting area on the cylinder fall. each pair of ring members and adapted to separate the ring members from each other is a spacer having an effective radial thickness greater than the thickness of the strip material of which the spacer is formed. The preferred embodiment of the spacer is substantially circular in form and has substantially U-shaped portions arranged at intervals thereon so that the effective cross-sectional area of the spacer is greater than the crosssectional area of the material itself from which the spacer is made. The spacer preferably is formed of ribbon steel and is positioned between the ring members so that the lateral edges thereof contact the ring members. The U-shaped portions preferably are arranged so that the effective radial thickness of the spacer is slightly less than the radial thickness of the ring members used in the packing structure so that'the ring members rest firmly on the spacer. VWhen a piston packing of this kind is used as an oil ring passages are provided in the ring expander and in the spacer so that oil may flow through these passages and through ports provided for this' purpose in the piston at the bottom of the ring groove. v

Positioned between :til

Since. the ribbon steel of which the spacer is formed is quite thin as compared to its width. the bounding walls of the passages are substantially short since they are only as long as the thickness of the ribbon material of which the spacer is formed, and hence the opportunity for carbon to collect on these radial bounding walls is minimized. If carbon should form in the passages it will attain a thickness no greater than the length of the bounding walls and, therefore, the carbon formation will be thin because the bounding walls of the passages are substantially short. This thin wall of carbon, if it should form in the passages, will be swept away by oil owing therethrough and the passages, therefore, will not become blocked by carbon forming therein.

Besides overcoming the deficiencies mentioned above of piston packings as used heretofore, a piston packing constructed according to my invention, and as briefly described above, is cheap to manufacture since all the constituent members may be formed of ribbon steel and the only operation required in forming the members is to bend the ribbon steel to proper shape.

Having thus briefly described my invention one object thereof is to provide a multiple-piece piston packing wherein oil passages through the spacer ring will be formed with extremely short bounding walls.

Another object of my invention is to provide a multiple-piece piston packing which may be formed entirely of ribbon material, such as strip steel.

A further object of my invention is to provide a. multiple-piece piston packing which may be used as an oil ring.

A more specific object of my invention is to provide a multiple-piece piston packing which is cheap to manufacture and which will provide an effective seal between the piston and the cylinder in which it reciprocates.

Other objects and advantages will be apparent to those skilled in the art from the following description wherein reference is made to the drawing illustrating several preferred embodiments oi my invention and wherein similar reference numerals designate similar parts throughout the several views.

In thevdrawing, Fig. l shows a piston provided with a piston packing constructed according to my invention.

Fig. 2 of a second embodiment of my invention.

Referring to theA gures, a piston I is shown therein comprising a head 2, a skirt 3, wrist-pin bosses 4 and ring grooves 5. 'I'he piston, however,

ring members 1 have a gap 8 therein between the' ends of the ribbon steel of which the ring'members are formed so that they may, expand and form in the passages I4, th'e formation willl be substantially thin, since the bounding walls of the passages 'are short, and the formation, therefore,

will not have sumcient strength to withstand the pressure of the oil whereby the carbon formation in the passages will be removed by the oil flowing therethrough. If thepassages-Il are arranged between the bent or ll-shaped portions of contract as they pass over irregularities in the cylinder wall when the piston reiprocates in.the

cylinder.

Positioned between the bottom ofl the ring groove 5 and the rear faces of the ring members 1 is a sinuous expander 9 adapted to exert radial pressure on the ring members 'I so that the ring members, in turn, exert a substantially high pressureper unit of contacting area on the cylinder wall, whereby the ring members effectively remove an adequate amount of oil therefrom.

Th'e.' expander 9 may have passages 9a arranged at intervals therein and adapted to permit excess oil, removed from the cylinder wall bythe ring members lI, to pass therethrough to the bottom of the ring groove 5 where it may pass into" the interior of the piston I through ports I0 therein provided for that purpose.

Positioned between the ring members I and adapted to separate the ring members from each other is a spacer II, which' spacer and the construction thereof constitute the essence of my invention. A

In the embodiment shown in Figs. 1 to 4, inclusive, the spacer II is substantially circular in form and has outwardly curved, U-shaped portions A- I2 arranged4 at intervals thereon so that the effective cross-sectional area of the spacer II is much greater than the crosssectional area-ofthe strip of material from which the spacer-is made. The spacer I I preferably is formed of ribbon steel or other similar material and is arranged, as shown, edgewise between the ring members fI so that only the lateral edges of the spacer contact the ring members. 'I'he spacer II mayv have a -gap I3,between the ends thereof so that it may expand and contract with the ring members 'I as the ring members encounter irregularities in the cylinder wall.

.When the piston packing 6 isto be used as an oil ring, the spacer I I h'as -formed in the portions thereof between the substantially U-shaped portions I2 'a plurality of passages I4 preferably arranged in staggered formation, as shown2 clearly in Fig. 1, and extending through thematerial. Excess oil, removed from the cylinder wall by' the ring lmembers l, will drain through these passagesld into the space behind the packing structure `6 and from there it may drain through ports I0 into th'e hollow interior of the piston I.' These passages `I4 in the spacer II may be-of any size, shape and arrangement and it will be evident that the bounding Walls -of the passages I 4 will be Aonly as long as the thickness of the ribbon material from which the spacer II is formed and, hence, the opportunity for carbon to collect on these radial-bounding Walls will be minimized` As stated above, if carbon should substantially,

Fig.2.'

Other arrangements may be used without devlatingA from the scope ofl my invention, ,and while I j describe a particularconstructlon embodying my invention, it is evident that the construction maybe varied in many particulars, and I` do not limit myself to the form and arrangement shown and described above. For instance, a piston packing Ii v,constructed according to my invention may include more than two ring members 1, andeach pair thereof may be separated by a spacer II. Also, as shown in Fig. 5, the spacer II used to separate the ring members- 'I from' each other may be formed and arranged so that the U-shaped portions I2a are curved inwardly and then the passages Ida will be positioned in staggered formation in the portions of the expander between the substantially U-shaped portions I 2a and in proximity to the cylinder wall.' Although I prefer to form all the constituent parts of my piston packing of ribbon steel, other materials also may be used.

What I claim as new and desire to' secure by Letters Patent, is:

1; A composite piston ring for internal comfbustion engines, comprising al pair of split cylinder wall contacting elements disposed to present their edges to a cylinder wall, an inner expanding spring provided with a plurality of parts in radial thrust engagement with said elements, and a spacer element between said cylinder con- -tacting elements comprising a ribbon-like metal element of generally annular outline', said spacer element being corrugated and disposed between said cylinder contactingelements to present its edgesthereto Kand centered on said inner expanding spring with the corrugations in engage- 4'ment with the parts of the spring, whereby wear between the element and spring is minimized.

2. A composite piston ring for -internal com- 3. Ina composite ring having a pair of steel cylinder wall contacting elements and an expander coacting therewith, a thin metallic ribbon-like spacer for said elements of generally annular outline having a plurality of relatively small corrugations therein, said spacer being disposed on'edge between said elements to space the same and having a plurality of oil drainage 'openings extending therethrough.

DALLAS M. SMITH.

CERTIFICATE oF CORRECT-10N. Patent No. 2,561,90LA. october 51, 19m.

DALLAS M. SMITH.

It is herebyrv certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page l, first column, line 10, after the word "passages" strike out the comma; line 55,

for "fall" read wa11; page2, first column, line )4.6, after the period and before "'.l'hel insert the following --As clearly shown in the drawings, the U-shaped portions 12 are of substantially the .same radial dimension andeircumferentiai extent, and these dimensions are also substantially the same as the axial dimension of the spacer and the intervals between the U-shaped formations.;

and that the said Letters Patent should be read with thiseorreetioo therein that the same may confom to the record of the case in the Patent Office.

signed and sealed this `6th day of February, A. D. 19LA5.

Leslie Frazer a (Seal) Acting Commissioner of Patents. 

